custom pages (page + blog) not showing posts

I have searched around but have not been able to find an answer. I have a www.remarpro.com website. Custom pages were made for me (template called page + blog) and they had been working fine. But I have tried on my own to create new pages, selecting the template called page + blog, but these new pages I’ve created are not showing the posts that i have assigned to them. I think I am missing a step about how to assign the posts to them maybe…

Any advice?